Tooth and holder having detents and resilient retaining means



April 967 w. M. TROEPPL ETAL 3,312,003

TOOTH AND HOLDER HAVING DETENTS AND RESILIENT RETAINING MEANS Filed May 25, 1964 INVENTORS W/LL/AM M TROEPPL JOHN G. BENETT/ United States latent ()fifice 3,312,063 Patented Apr. 4, 1967 3,312,003 TOOTH AND HOLDER HAVING DETENTS AND RESILIENT RETAINING MEANS William M. Troeppl, Santa Clara, and John G. Benetti,

Cupertino, Calif., assignors, by direct and mesne assignments, of one=half to Gerald A. Petersen, Santa Clara, Calili, and one-half to Anita E. Petersen, Saratoga, Calif.

Filed May 25, 1964, Ser. No. 369,780 3 Claims. (Cl. 37-142) This invention relates to a new and improved tooth and holder having detents and resilient retaining means for earth-digging equipment. This invention is an improvement over Peterson Patent No. 2,968,880.

The tooth illustrated and described in the aforementioned Peterson patent provides a hard unitary tooth for an earth-digging machine having a tapered distal portion which performs the digging function and a bifurcated proximal portion composed of two prongs separated from each other by a rectangular slot which extends forwardly from the proximal end of the tooth. In said invention there further is illustrated and described a toothholder formed with a pair of recesses extending rearwardly from the forward end so that the resulting shape of the holder as viewed in front elevation is substantially H-shaped with a vertical web fitting into the slot in the proximal end of the tooth. To hold the tooth in the holder there further is provided a resilient insert which extends through a hole in the web and, when the tooth is in place, is jammed between the inner vertical surfaces of the tooth prongs and the walls of the web, thereby preventing unintentional dislodgement. Accordingly, a principal feature of the aforesaid Peterson patent isthe fact thatt'he use of bolts, metal keys and similar fastening means to secure the tooth to the shank is eliminated, thereby likewise eliminating much of the ditliculty theretofore occasioned in securing teeth in holders. The resilient insert is protected from wear and abrasion. Further, the use of the resilient insert accommodates minor variations in the construction of the tooth and holder, thereby making close tolerances unnecessary, and further accommodating 'wear of the parts with the passage of time. Additional advantages of such tooth and holder are the facility with which the tooth may be installed and removed and the fact that no special tools are required for such purpose. Installation or removal of the tooth from its holder is accomplished with a minimum of time.

Althoutgh the foregoing features and advantages of the tooth and holder in accordance with Peterson Patent No. 2,968,880 have led to widespread commercial success, certain operating conditions create an environment for which the tooth and holder and its resilient retaining means are not suitable. More specifically, the undesirable environment for such tooth, holder and resilient insert retaining means occurs when a lubricant is employed in the cutting operation or when the nature of the earth being cut is particularly slippery. Under such conditions the natural frictional engagement of the resilient insert with the side walls of the prongs of the tooth and of the web of the holder is diminished, permitting a sliding of the tooth relative to the holder and its eventual dislodgement. It is a principal purpose and object of the present invention to provide detents on the walls of the tooth prongs and of the web of the holder which engage the resilient insert retaining means and enhance the frictional retention of the tooth in the holder and also distort the retaining means into a sinuous shape, all of which prevent unintentional dislodgernent of the tooth from its holder.

Another feature of the present invention is the provision of a transverse hump in the top and bottom of the tooth extending transversely across the tooth immediately forward of the forward end of the slot. The humps thus formed are, in the assembled position of tooth and holder, in close proximity to the forward edge of the holder. By reason of the extremely hard nature of the tooth, the hump protects the forward edge of the holder from Wear during the digging operation. A feature of the invention is the positioning of the hump in such close proximity to the forward edge of the holder extending entirely transversely across the width of tooth and holder at an approximately constant thickness.

Still another feature of the invention is the provision of improved means for dislodging the tooth from its holder when it is worn and must be reversed or replaced. For

such purpose, holes are formed in the top and bottom flanges of the tooth holder in registry with the forward end of the slot of the tooth. By driving a tapered instrurnent through the aligned holes, the tooth may be forced forwardly away from the holder despite the frictional engagement of the retaining means with tooth and holder and further despite the gripping of the detents with said retaining means.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. 1 is a plan view of the tooth in accordance with the present invention.

FIG. 2 is a longitudinal sectional View taken substantially along the line 2-2 of FIG. 1.

FIG. 3 is a side elevational view of the toothholder employed with the tooth of FIGS. 1 and '2.

FIG. 4 is a horizontal, sectional view taken substantially along the line 4-4 of FIG. 3.

FIG. 5 is a fragmentary enlarged longitudinal sectional view showing the tooth, holder and resilient retaining means in assembled position.

The tooth 11'. which is the subject of this invention has forwardly converging top and bottom distal surfaces 12, 13? extending across the width of the tooth and terminating irr'a truncated front edge 14 providing top and bottom cutting edges 16, 17. A feature of the invention is the fact that the tooth is reversible in that if edge 16 is worn, the tooth may be reversed and edge 1'7 used and reversal of the tooth alternated until the working portion of the tooth is exhausted. The side edges 18 are substantially vertical and parallel although they converge slightly rearwardly. Proximal prongs 19 or roots are separated from each other by a slot 21 which extends forwardly from the proximal end of the tooth. The side walls 22 of slot 21 are substantially parallel to side edges 18, it being understood that the outer side walls 23 of prongs 19 are essentially coextensive with side edges 18 of the distal portion of the tooth. The rearward ends 24 of prongs 19 slant outwardly forwardly providing abutting ends 26 which bear the rearward thrust against holder 31.. The forward end 27 of slot 21 is rounded. It will be seen that the edges 22, 23, 24, 26, and 27 are not vertical but are bevelled as is best shown by reference numeral 24 in FIG. 2.

Immediately forward of end 27 of slot 21 are transverse humps 28 which function to protect the forward edge of toothholder 21 from abrasion. Humps 28 are positioned immediately forwardly of the forward ends of holder 31 in the assembled position of the tooth l1 and holder 31 as hereinafter explained and are of substantially uniform thickness transversely across the tooth.

A particular feature of the invention is the provision of a pair of inwardly projecting detents 29 in walls 22 adjacent the proximal end of the tooth. A further feature of 3 the invention is the provision of steps 30 which tape-r 'rearwardly in the proximal half of each prong as contrasted with the substantially parallel or horizontal surfaces 30a in the forward half of each prong.

Holder 31 has a proximal end 32 here shown in the form of a rectangular bar which is suitable for attachment to a permanent portion of the digging equipment with which the tooth and holder are employed. Various means may be used to secure holder 31 to such equipment and for such purpose semi-circular cutouts 33 may be employed. Holder 31 is essentially H-shaped in the sense that it is formed wit-h a vertical web 36 extending between an upper transverse member 37 and a lower transverse member 38. The cross-sectional shape of web 36 is such as to fit inside slot 21 of tooth 11 with a slight clearance between the walls 39 of web 36 and the walls 22 of slot 21. The spacing between the opposed top and bottom Walls 41 of top and bottom members 37, 58 respectively is slightly greater than the space in between walls 311a and inwardly the walls 42 are spaced apart slightly greater than the distance between the converging walls (it) of tooth 11. The recesses between portions 37, 38 terminate in ends 43 against which points 26 abut.

Extendingtransversely horizontally through Web 36 is a hole 46 which receives a resilient insert 47 formed of rubber, neoprene, or the like, which is preferably circular in cross-section and of a diameter approximately equal to that of hole 46. The length of insert 47 is substantially greater than the width of web 36 'and preferably is about equal to the width of the holder 31. Web 36 is grooved rearwardly of hole 46 but the spacing between web 36 and walls 22 of tooth 11 is less than the thickness of insert 47 so that the insert 47 is squeezed between walls 22 and web 36. Under normal operating conditions the compression of insert 47 is sufficient to hold the tooth in its holder against unintentional dislodgment. However, a feature of the present invention is the provision of the detents 29 on prongs 19 and also forward detents 48 and rearward detents 49 on side walls 39 of web 36. The detents 48 and 49 are spaced apart and are located so that detents 29 are between detents 48 and 49 in the assembled position of toothholder as is best shown in FIG. 5. This arrangement of detents 29, 48, 49 imparts to the insert 47 a sinuous shape 'as is shown in FIG. which enhances the frictional engagement of the insert with the walls of tooth and web respectively, and also permits the respective detents to dig into the insert to hold the assembled parts in place.

To facilitate dislodgement of tooth 11 from holder 31 when it is worn and must be reversed or replaced, a semicircular cutout 51 is formed in the top and bottom for- 'ward edges of portions 37, 38, respectively, so that cutout portions 51 are substantially in registry with the forward 'end 27 of slot 21. Hence, a tapered tool may be inserted in the aligned openings to force the tooth 11 to the left as viewed in FIG. 5, and thus to withdraw the tooth from its holder despite the function of retaining means 47.

In installing the tooth, prongs 19 are inserted in the openings to either side of web 36, and the proximal ends 24 of the tooth bend insert 46 which previously has been inserted transversely through hole 46 to assume the position shown in FIG. 5. Insert 47 bears against walls 22 and 39. Further, detents 19 dig into insert 47 as do detents 48 and 49. The combined functions of the insert 47 and detents 29, 48 and 49 are such that in normal usage of the equipment even in very viscous environments and despite wear, vibration and abrasive action of the material being dug, the tooth will not ordinarily be separated from its holder.

When it is necessary to remove tooth 11, the tooth may be dislodged in a manner previously indicated.

By reason of the fact that tooth 11 is formed of a unitary piece of hard, abrasive resistant steel which, nevertheless, has 'a certain amount of malleability, materials which are quite abrasive may be dug and considerable shocks may be absorbed by the tooth during the digging action. The holder 31 is of a more resilient material which permits a certain amount of bending and flexure to absorb much of the strain of the digging 'action. Essentially, therefore, holder 31 is of a less abrasive resistant material. Accordingly, the humps 28 being positioned immediately ahead of the forward ends of holder 31 protect the holder from contact with the abrasive material being dug. Reinforcing ridges 52 and gussets 53 (see FIG. 3) further strengthen holder 31 against the shocks and strains of the digging action.

What is claimed is: e

1. In combination in earth-digging equipment, a tooth formed of a unitary piece of hard material having a distal portion formed with a cutting edge and a proximal portion having top and bottom faces formed with a longitudinal slot extending forwardly from the proximal end of said tooth to divide said proximal portions into two prongs, said slot formed with substantially parallel longitudinal walls transverse to said top and bottom faces and a first detent on at least one said longitudinal wall; and a holder formed with a recess to receive said prongs, said holder having a web extending through said recess to fill said slot, said web formed with a hole transverse to said walls and with at least one second detent on at least one side of said Web; and a resilient insert extending through said hole and jammed between said web and at least one of said prongs, said detents gripping and deforming said resilient insert to restrain unintentional withdrawal of said tooth from said holder, said slot and holder formed and positioned to provide aligned openings for insertion of a tool to force said tooth out of said holder, said opening in said holder formed in the forward edge of said holder and the forward end of said slot loc'ated' forwardly of the forward edge of said holder.

2. In earth digging equipment, a tooth formed of hard material having a distal portion formed with a cutting. edge and a proximal portion formed with a longitudinal slot extending forward from the proximal end of said tooth dividing said tooth into prongs;

a tooth-holder formed with a pair of recesses to receive said prongs and terminating in a forward end rear-. ward of the forward end of said slot, whereby a tool may be inserted in front of the forward end of said holder and into the forward end of said slot to force said tooth away from said holder;

and retaining means for detachably retaining said tooth in said holder.

3. The combination of claim 2, in which the forward end of said slot is curved and in which a curved groove is formed in said forward end of said holder, said curved forward end of said slot and curved groove outlining a closed curved opening for said tool.

References Cited by the Examiner UNITED STATES PATENTS 2,924,490 2/ 1960 Haushalter. 2,925,673 2/1960 Sennholtz 37--1'42 2,955,832 10/1960 Gary. 2,968,880 1/1961 Petersen 37-142 FOREIGN PATENTS 213,291 2/ 1958 Australia.

ANTONIO F. GUIDA, Acting Primary Examiner.

ABRAHAM G. STONE, A. E. K-OPECKI,

Assistant Examiners. 

1. IN COMBINATION IN EARTH-DIGGING EQUIPMENT, A TOOTH FORMED OF A UNITARY PIECE OF HARD MATERIAL HAVING A DISTAL PORTION FORMED WITH A CUTTING EDGE AND A PROXIMAL PORTION HAVING TOP AND BOTTOM FACES FORMED WITH A LONGITUDINAL SLOT EXTENDING FORWARDLY FROM THE PROXIMAL END OF SAID TOOTH TO DIVIDE SAID PROXIMAL PORTIONS INTO TWO PRONGS, SAID SLOT FORMED WITH SUBSTANTIALLY PARALLEL LONGITUDINAL WALLS TRANSVERSE TO SAID TOP AND BOTTOM FACES AND A FIRST DETENT ON AT LEAST ONE SAID LONGITUDINAL WALL; AND A HOLDER FORMED WITH A RECESS TO RECEIVE SAID PRONGS, SAID HOLDER HAVING A WEB EXTENDING THROUGH SAID RECESS TO FILL SAID SLOT, SAID WEB FORMED WITH A HOLE TRANSVERSE TO SAID WALLS AND WITH AT LEAST ONE SECOND DETENT ON AT LEAST ONE SIDE OF SAID WEB; AND A RESILIENT INSERT EXTENDING THROUGH SAID HOLE AND JAMMED BETWEEN SAID WEB AND AT LEAST ONE OF SAID PRONGS, SAID DETENTS GRIPPING AND DEFORMING SAID RESILIENT INSERT TO RESTRAIN UNINTENTIONAL WITHDRAWAL OF SAID TOOTH FROM SAID HOLDER, SAID SLOT AND HOLDER FORMED AND POSITIONED TO PROVIDE ALIGNED OPENINGS FOR INSERTION OF A TOOL TO FORCE SAID TOOTH OUT OF SAID HOLDER, SAID OPENING IN SAID HOLDER FORMED IN THE FORWARD EDGE OF SAID HOLDER AND THE FORWARD END OF SAID SLOT LOCATED FORWARDLY OF THE FORWARD EDGE OF SAID HOLDER. 